Deal activity by companies from chocolate makers to a nuclear submarine manufacturer buoyed Wall Street confidence on Monday, lifting US stocks after last week’s strong gains. The Dow Jones Industrial Average closed up 2 per cent at 10,226.94, its highest level since October last year.

The S&P 500 gained 2.2 per cent to 1,093.08 and the Nasdaq Composite climbed 2 per cent at 2,154.06.